#!/usr/bin/env python3
"""M2-600M cascade adapter with deterministic timed-prompt repair.

Audio/code targets and manifests remain immutable. Every presentation passes
through ``timed_prompt.repair_prompt``; repair facts are returned in accounting
so the trainer can prove the observed timed/untimed mixture.
"""
import json
import os
import numpy as np
from timed_prompt import repair_prompt

MODES = ('instruction', 'reference')
TAR_MEMBER_MAP = '/e/scratch/reformo/schuhmann1_moss/out/m2_600m_ladder/tar_member_map/manifest.json'

class CascadeRecords:
    def __init__(self, manifest):
        from pathlib import Path
        self.manifest_path = Path(manifest)
        spec = json.loads(self.manifest_path.read_text())
        assert spec['status'] == 'complete' and spec['presentations'] > 0
        root = self.manifest_path.parent
        self.spec = spec
        self.phase = str(spec.get('phase') or spec.get('ladder_stage') or self.manifest_path.parent.name)
        self.offsets = np.load(root / spec['offsets'], mmap_mode='r', allow_pickle=False)
        assert len(self.offsets) == spec['presentations'] + 1
        assert self.offsets.dtype == np.int64 and int(self.offsets[0]) == 0
        self.order = np.load(root / spec['order'], mmap_mode='r', allow_pickle=False)
        assert len(self.order) == spec['presentations']
        assert self.order.dtype in (np.dtype('uint32'), np.dtype('int64'))
        # Full uniqueness is established once by the manifest verifier.  Never
        # materialize 48M Python ints/sets independently on all 128 DDP ranks.
        assert int(self.order.min()) == 0 and int(self.order.max()) == spec['presentations'] - 1
        self.path = root / spec['records']
        self.fd = os.open(self.path, os.O_RDONLY)
        assert int(self.offsets[-1]) == self.path.stat().st_size
        if 'records_bytes' in spec:
            assert self.path.stat().st_size == spec['records_bytes']
            assert (root / spec['offsets']).stat().st_size == spec['offsets_bytes']
            assert (root / spec['order']).stat().st_size == spec['order_bytes']
        import sys
        sys.path.insert(0, '/e/scratch/reformo/schuhmann1_moss/code/m2_20k_score')
        from dataset import ShardReader
        from tar_member_map import TarMemberMap

        class MappedShardReader(ShardReader):
            def __init__(self):
                # ShardReader uses the same bounded capacity for Parquet
                # reference tables as for TAR member dictionaries.  TAR
                # dictionaries are overridden below, but Parquet tables still
                # need a non-zero LRU (capacity=0 caused an immediate eviction
                # followed by move_to_end(KeyError) in S1 smoke 1892952).
                super().__init__(capacity=16)
                self.packed_members = TarMemberMap(TAR_MEMBER_MAP)

            def member(self, path, name):
                offset, size = self.packed_members.locate(path, name)
                return self.bytes_at(path, offset, size)

        self.reader = MappedShardReader()

    def __len__(self):
        return len(self.order)

    def row(self, index):
        j = int(self.order[index])
        start, end = int(self.offsets[j]), int(self.offsets[j + 1])
        return json.loads(os.pread(self.fd, end - start, start))

    def example(self, index, packer):
        row = self.row(index)
        mode = row['mode']
        form = row.get('form', 'A')
        assert mode in MODES, row['uid']
        assert form in ('A', 'B'), row['uid']
        meta = self.reader.record(row['record_locator'])
        assert meta['uid'] == row['uid']
        if 'moss_frames' in meta:
            meta['frames'] = int(meta['moss_frames'])
        else:
            # Sidecar element JSONs carry no moss_frames key (pre-upload state);
            # frame count comes from the manifest locator (validated in codes()).
            meta['frames'] = int(row['target_locator']['full_frames'])
        codes = self.reader.codes(row['target_locator'])
        assert len(codes) == meta['frames']
        meta = dict(meta)
        meta['prompt'], prompt_info = repair_prompt(
            meta, caption=row.get('bude_caption'), form=form, mode=mode,
            presentation=int(index), phase=self.phase)
        reference = None
        if mode == 'reference':
            assert row.get('reference_uid') and row['reference_uid'] != row['uid']
            assert row.get('reference_locator')
            reference = self.reader.codes(row['reference_locator'])
            assert 0 < len(reference) <= 37
        result = packer.pack_mode(meta, codes, mode, reference)
        result['accounting'] = {'uid': row['uid'], 'mode': mode, 'form': form,
                                'frames': len(codes),
                                'target_audio_hours': float(meta['dur_s']) / 3600,
                                'reference_frames': len(reference) if reference is not None else 0,
                                'prompt_timed': bool(prompt_info['timed']),
                                'prompt_eligible': bool(prompt_info['eligible']),
                                'duration_tags': int(prompt_info['duration_tags']),
                                'prompt_format_id': prompt_info['format_id']}
        return result